Steam-boiler and furnace



(No Model.) 2 Shets-SheethL W. s. POST au H. 'DE W. SAWYBR.

STBAMIBOILER AND'PURNAGE.

No. 351,652.. 'Patented 001;. 26, 1886.

l v r 2 Sheets-Shqef .j

W. s. POST au H. DE W. SAWYBB..

r STEAM BOILBR AND PURNGBV.

(NQ Modem No. 351,652 Patentfd oct. 26, 1886.

FUI-1.5.

FAiEQ.

' N. PETERS. mwmmmhur. wmwm. 0.a

UNITED STATES PATENT. OFFICE.

WILLIAM s. rOsT, or BOSTON, AND HOWARD DE W. sAWYER, or nnvnnn,

MASSACHUSETTS, ASSIGNORS TO THE COMPLETE COMBUSTION COMPANY,

OF PORTLAND, MAINE.

SPECIFICATIONV forming part of Letters Patent No. 351,652, dated October 26,1886. Application filed June 3, 18H6. Serial No. 203,999. (No model.)

l To aZZ whom it may concern: y

Beit known that we, WILLIAM yS. IO'sT and HOWARD DE W. SAWYER, residents, respectively, of Boston and of Revere, Massachusetts, haveinvented,jointly,newand useful Improvements in Steam-Boilers and Furnaces, of which the following, taken in connection with the accompanying drawings, is a specication.

This invention embraces certain improve- IO ments upon the apparatus set forth in the Letters Patent'No. 299,578, granted to us June 3,

1884, and in our pending application-forv pat-y ent led May 19, 1886, Serial No. 202, 631.

The distinguishing peculiarity of all our I5 boilers is the depending waterleg and the downward draft for the purpose of consuming the fuel and gases more perfectly and producing steam more rapidly.

Our present improvements relate to `the 2Q grate, to the form of the fire-box, and to the draft-inlets, the novel features being hereinafter described, and especially referred to in the appended claims.

In the drawings, Figure 1 is a vertical lou- 2 5 gitudinal section through a boiler embodying our improvements. Fig. 2 is an end view; and Fig. 3 a transverse section on the line x m, Fig. 1.

A represents the .cylindrical shell of the '5o-boiler, and B the nre-pot placed wholly within the shell A, held in place by ordinary staybolts and crown-sheet bars, (not shown,')` and made cylindrical ,except where flattened at the crownsheet C, to give sufficient water and 3 5 steam space above the fire-pot, and the series of tubular fines D. This form and relative arrangement of the boiler and fire-pot constitute a feature of our invention, and it is ad` vantageous because these parts, formed of 40 heavy boiler-plate, can "thus be made and combined together with greater cheapness, strength,and efficiency than in any other form. The space within the fire-pot and above the grate we term the fuel-chamber,7 and that below thegrate and'in part beyond the waterleg we designate the combustion-chamber.7

The inner portion, vE, of this latter chamber is Y much enlarged,as compared with the drawings in our former patents, to afford space for the workmen in setting the tubes or making any repairs. To facilitate this work, the front and rear walls of this inner chamber are made vertical and unobstructed.

F is the body of the water-leg, and G its oblique foot, both opening into and communicating freely with the Water lcontained in the hollow water-walls H at each side of the boil-v er, and being open at the top to allow free circulationfof water and escape of steam into the steam-space. The leg is iianged and riveted water and steam tight to the crown-sheet C, and also to the side walls of the fire-box, as is the foot G. The upper portion of the `waterleg is shown strengthened by a series of staybolts, I, .extending from its front to its rear face, and similar stays may be provided for the foot,

y if desired. v

face to support the fuel, and preserves open' spaces for the downward draft, thus greatly increasing the production of. steam, since the descending amebetweeu the upper tubes impinges directly upon those of the lower series. A result closely approximating to that secured by this zigzag arrangement is attained by placing the tubes of one series directly beneath those of the other series, since the descending iiames pass transversely by thc several tubes and impart their heat to the water" fiowing through them, thus rapidly converting it into steam. y The caloric current keeps the tubes clean, the downward current being necessitated by the depending leg and the draft-iulets above the grate, and serving to heat both ranges of tubes to practically the same degree.

yThe oblique arrangement of the tubes J is desirable to afford clearance for steam which -is or may be formed in them, giving an easy and natural flow of the water rearwardly and upwardly; but when the water is admitted under pressure from the front the tubes may be placed horizontally. The tubes .I are shown as entering the oblique front ofthe water-leg at aright angle, and, extending downwardly from a bend or elbow, K, they are screwed or swaged into a hollow ledge, L, forming part of the front water-wall, and furnished with a removable front plate, M, in order to facilitate any needed repairs. The bend or elbow in cach tube gives to each a limited yield independent ofthe others, to provide for unequal expansion by heat, and in case of leakage one tube can be removed and another substituted without disturbing the others. Ifdesired, the leg F and ledge L may be re-enforeed by an additional thickness of metal along the line of insertion of the tubes.

The fueldoorN, manhole door O, and draftdoor I? in the end of the boiler may be furnished with thick, flattened iron rings R, to which the end plates may be firmly bolted, to secure tightjoints and to guard against warping. \Vithin the draft-door I we employ a perforated door or doors, Q, as ameans of ad mitting air-jets to the front of the fuel which maybe piled againstit. Through these doors, when desired, the fire may be stirred or withdrawn, the corrugated surface or zigzag arrangement of the grate facilitating these operations. Ashes may be removed, or the surface of the foot portion G of the water -leg cleared of obstructions, through the man-hole or ash-door O,

In our former invention we represented a lateral draft into the sides of the fire through hollow stay-bolts passing entirely through the water-walls to the air outside the boiler-shell. \Vith our present improvements we introduce through the water-space at each side of the fire-box one or more air tubes, T, running from the front rearwardly about parallel to the grate, but somewhat above it, and we extend hollow stay-bolts S, or short open tubes, from the tubes T through the walls of the fireboX, to admit air in jets to the edges of the fuel. The air, being thus warmed by its pas sage in tube T through the hot water, has no tendency to lower the temperature, but promotes combustion materially. XVe also provide a. perforated air-pipe, U, extending from outside the boiler-shell transversely across the rear end of the fuel-chamber, and serving to deliver air in downward jets at the inner end of the chamber. A valve or regulatingcover to control the amount of air admitted may be provided. Owing to the downward draft in our furnace this pipe is subjected to but a moderate heat. Air-jets are also admitted below the grate, to assure the perfect combustion of the inflammable gases; but as the heat is there too intense for an unprotected tube we pass air-tubes V and XV (either or both) from' the outer air through the toe and heel of the foot G of the waterleg, and we provide a series of short hollow bolts, Z, opening airpassages from such tubes into the combustion -chambcr. (See Fig. l.) The amount of air admitted at these points is also within the control of the engiueer.

\Ve claim as our joint invention* l. The cylindrical boiler-shell A, having fixed within one end of it the firebox B of a. generally cylindrical form, but attened at its top, as described, in combination with a depending water-leg secured to the top and sides of the tire-box, and with an oblique watergrate, substantially as set forth.

2. The boiler A and fire-pot B, with waterwalls H between them, in combination with an oblique water-grate, a depending water-leg, and a series of stay-bolts, I, extending from front to rear of the water-leg, substantially as set forth.

3. In a downdraft heating apparatus, a de pending waterleg, in combination with a multiple watergrate consisting of two or more distinct series of independent water-tubes, among and between which the ignited gases and carbon pass downwardly, whereby the heated current comes transversely into contact with the tubes of the several series successively, for the purpose set forth.

4. The improved water'- grate herein described, formed of two distinct series of par allel metallic tubes arranged in a zigzag rela- `tion to each other, so as to break joints, and

having a free water-circulation through them, substantially as set forth.

5. The described multiple water-grate, consisting of the independent oblique tubes J, arranged in two or more distinct planes to alternate vertically with each other, and each provided with the bend or elbow K, substantially as set forth.

6. The shell A, fire-pot B, water-walls H, and water-leg F, with its foot G, in combinanation with the zigzag multiple watergrate extending obliquely across the nre-pot, with the tubes of its upper series arranged over the spaces between the tubes of thelower series, substantially as set forth.

7. In a steam-boiler or furnace having water-walls each side of the fire-pot, and a down` ward draft, the depending water-leg, and a water-grate connected thereto, in combination with air-tubes T, extending rearwardly within the water-spaces H, and with aseries of transverse tubes, S, opening from the air-tubes T into the tire-pot along the sides of the fuel, substantially as set forth.

8. In a steam-boiler or furnace, the combination of a water-grate and depending waterleg,separating the fuel-chamber from the combustion-chamber, with a perforated air-pipe, U, above the grate, serving to introduce currents of fresh air at the rear of the fuel-chamber, substantially as set forth.

9. In a heatingapparatus, the combination of a water grate and depending water-leg, separating the fuel-chamber from the combustion-chamber, with one or more air-pipes, V

IOO

IIC

W, introduced laterally through the footof 'Intestimonywhereof we have signed our .the water-leg below the grate, `and with a senaunes to this specification, in the presence of ries of short hollow bolts, Z, leading from said two subscribing witnesses, on this 27th day of pipes into the combustion-chamber, substan- May, A. D. 1886. tally'as set forth. l

10. The combination of the boiler A, inter- WILLIAM. S. POST." nal fire-box, B, depending Water-leg F, and HOWARD DE W. SAWYER. zigzag oblique Water-grate J with the perforated door` Q and unperforated door P, located Witnesses: Io at the foot of said grate, substantially as set l A. HfSrENoER,

forth. GEORGE A. AYER. 

